A function in a bash script is a reusable block of code that can be executed by calling its name. Functions help to organize and structure your code and can be used to perform a specific task.

Lets create function

1. Open your terminal or shell.
2. Create a new file using a text editor of your choice. For example, you can use the nano editor to create a file called “functions.sh”:

nano functions.sh

3. Type the following code into the file:

#!/bin/bash

# Defining a function
function greet() {
  echo "Hello, $1"
}

# Calling a function
greet "book"

4. Save the file and exit the editor.
5. Make the file executable by running the following command in the terminal:chmod +x functions.sh

chmod +x functions.sh

6. Finally, run the script by typing:

./functions.sh

You should see the message “Hello, book” printed in the terminal.

And that’s it! This is a simple example of how to use functions in a Bash script. Functions are blocks of code that can be executed multiple times from different parts of the script. In Bash, you define a function using the function keyword, followed by the function name and the commands in braces.